package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */

@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
//    private class VoucherOrderHandler implements Runnable{
//        @Override
//        public void run() {
//            while (true){
//                try {
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    HandleVoucherOrder(voucherOrder);
//                } catch (InterruptedException e) {
//                    log.error("处理订单异常",e);
//                }
//            }
//        }
//    }
    private class VoucherOrderHandler implements Runnable{
        String queueName="stream.orders";
        @Override
        public void run() {
            while (true){
                try {
                    // 从队列中获取订单
                    //XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.orders >
                    List<MapRecord<String, Object, Object>> list= stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1","c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    // 如果队列为空
                    if (list == null || list.isEmpty()) {
                        continue;
                    }
                    //如果不为空，解析订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    HandleVoucherOrder(voucherOrder);
                    // 5确认消息
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }
        }
    private void handlePendingList() {
        while (true){
            try {
                // 从pending-list中获取订单
                //XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.orders 0
                List<MapRecord<String, Object, Object>> list= stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1","c1"),
                        StreamReadOptions.empty().count(1),
                        StreamOffset.create(queueName, ReadOffset.from("0"))
                );
                if (list == null || list.isEmpty()) {
                    //如果pending-list为空，跳出循环
                    break;
                }
                //如果不为空，解析订单信息
                MapRecord<String, Object, Object> record = list.get(0);
                Map<Object, Object> value = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                HandleVoucherOrder(voucherOrder);
                // 5确认消息
                stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
            } catch (Exception e) {
                log.error("pending-list处理订单异常",e);
                try {
                    Thread.sleep(20);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
        }
    }
    }



    private void HandleVoucherOrder(VoucherOrder voucherOrder) {
        // 1获取用户id
        Long userId = voucherOrder.getUserId();
        // 2创建锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        // 3尝试获取锁
        boolean isLock = lock.tryLock();
        // 4判断是否获取成功
        if (!isLock){
            log.error("不允许重复下单");
            return;
        }
        try {
            createVoucherOrder(voucherOrder);
        } finally {
            // 5释放锁
            lock.unlock();
        }
    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀尚未开始");
//        }
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束");
//        }
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足");
//        }
//        Long userId = UserHolder.getUser().getId();
//            //获取代理对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        boolean isLock = lock.tryLock();
//        if (!isLock){
//            return Result.fail("不允许重复下单");
//        }
//
//
//        try {
//            IVoucherOrderService proxy= (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            lock.unlock();
//        }
//
//    }
private IVoucherOrderService proxy;
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        Long userId = UserHolder.getUser().getId();
//        //1执行lua脚本
//        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(),
//                userId.toString()
//                );
//        //2判断结果是否为0
//        int r=result.intValue();
//        //2.1不为0 没有购买资格
//        if(r != 0){
//            return Result.fail(result == 1 ? "库存不足" : "不能重复下单");
//        }
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //2.2为0 有购买资格,把订单信息保存到阻塞队列
//        long orderId = redisIdWorker.nextId("order");
//        //TODO
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//        orderTasks.add(voucherOrder);
//        //3 返回订单id
//        //获取代理对象
//         proxy= (IVoucherOrderService) AopContext.currentProxy();
//        return Result.ok(orderId);
//    }

    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        Long orderId=redisIdWorker.nextId("order");
        //1执行lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),String.valueOf(orderId)
        );
        //2判断结果是否为0
        int r=result.intValue();
        //2.1不为0 没有购买资格
        if(r != 0){
            return Result.fail(result == 1 ? "库存不足" : "不能重复下单");
        }


        //3 返回订单id
        //获取代理对象
        proxy= (IVoucherOrderService) AopContext.currentProxy();
        return Result.ok(orderId);
    }
@Transactional
    public  void createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if(count > 0){
            log.error("用户重复下单");
            return ;
        }
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId())
                .gt("stock", 0)
                .update();
        if(!success){
            log.error("库存不足");
            return;
        }
//        VoucherOrder voucherOrder = new VoucherOrder();
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId( userId);
//        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
    }


}
